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I am building a MOSFET bridge to make sure my signals arrive at the load in the proper polarity regardless of the input polarity. My problem is the \$V_{gs}\$ voltages on the MOSFETs are at or exceed 20 V, this is the maximum \$V_{gs}\$ MOSFET I can find. What can I do to lower my \$V_{gs}\$ while still passing 11 V signals and having the proper MOSFETs turn on/off at the right times?

Here is the circuit. Battery voltage is 11 V, and op-amps are ±10 V, any lower on the op-amps causes MOSFET M3 to saturate.

enter image description here

EDIT: added a more clear schematic. N-channel MOSFET \$V_T=1\$, p-channel MOSFET \$V_T=-1\$. Link to the online circuit simulation simulation

I need to keep my \$V_{GS}\$ below 20 V, and the opamp rail voltages must be equal between opamps. The voltage source can swing between ±10 V. The common is always common, so just put a negative voltage into the value box on the simulator.

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    \$\begingroup\$ You may get more responses if you draw your schematic more clearly: include designators for every component, flow signals from left to right, and specify a ground node. \$\endgroup\$ – The Photon Jul 10 '12 at 20:11
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    \$\begingroup\$ Agreed, it's pretty unreadable as it is ;-) \$\endgroup\$ – Oli Glaser Jul 10 '12 at 20:32
  • \$\begingroup\$ Edited post to make the situation more clear. Check out the simulation link for an online simulation. \$\endgroup\$ – Z2012 Jul 11 '12 at 15:43
  • \$\begingroup\$ What about the diodes that are inside the mosfets, it looks like they will be a problem \$\endgroup\$ – Z2012 Jul 11 '12 at 23:29
  • \$\begingroup\$ Won't OA1 just saturate at the positive rail? \$\endgroup\$ – Scott Seidman Oct 9 '12 at 18:57
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Maybe you can use a full wave opamp rectifier instead of your MOSFET matrix.

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In a similar situation I used a series resistor (between driver and gate) + clamp zener (gate to source).

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